The U.S. Pat. Nos. to Gutridge et al 3,159,111; Pratt 3,586,286 and Horton 3,768,857 show various forms of locking means for lockingly engaging a container fitting to lock the container on a flatbed vehicle such as a trailer, truck or railway flatcar. The twist locks of the prior art are in position along the vehicle and are not adaptable to lock containers of various lengths on the same vehicle.